Justification:
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

This species is endemic to northern Australia. Subspecies coronatus is found along seven river systems in Western Australia and the Northern Territory. Its distribution is severely reduced, and it is no longer found on parts of the Pentecost and Fitzroy rivers. Subspecies macgillivrayi is found in eastern Northern Territory and north-west Queensland.

The species has a large global population estimated to be 10,000-28,000 individuals (Higgins et al. 2001). Subspecies coronatus numbers c.12,000; subspecies macgillivrayi numbers c.18,000 across 12 subpopulations.

Trend Justification: Subspecies coronatus is suspected to be declining owing to ongoing habitat loss and degradation (del Hoyo et al. 2007). Subspecies macgillivrayi is thought to have a stable population.

Livestock eat and trample the species habitat, seeking access to water. Fires are increasing in frequency since the advent of pastoralism, and have been detrimental in some places. These processes expose soil, leading to erosion and, ultimately, denudation and weed invasion of river banks which are then abandoned by the species. This has been ameliorated along some parts of the Victoria River where several large pastoral stations have excluded stock from riparian areas. The high and increasing densities of weeds along many rivers may eventually have an adverse effect (Garnett and Crowley 2000).